Pulp-digester



2 Sheets-Sheet 2.

(No Model.)

' R. LAVERY.

PULP DIGBSTER.

Patented July l, 1890.

No. 431,267. i

` Z w .ZJ 15a/@eden UNITED STATES PATENT OEEIcE.v

RICHARD LAVERY, OF BOSTON, MASSACHUSETTS.

PULP-DIGESTER.

SPECIFICATION forming part of Letters Patent N0. 431,267, dated July 1, 1890.

Application led March 9, 1889. Serial No. 302,616. (No model.)

T all whom it may concern:

Be it known that I, RICHARD LAVERY, of Boston, county of SiIffoll;,State of Massachusetts, haveinvented an Improvement in Pulp- Digesters, of which the following description, in connection with the accompanying draw* ings, is a specification, like letters on the drawings representing like parts.

This invention relates to pulpfligesters or boilers in which wood or other fibrous material is subjected to the action of a chemical solution to bleach it and reduce it to pulp.

vboiler-shell by bolts.

Prior to my invention the iron or steel shells of pulp digesters or boilers have been covered on their inner side, to obviate the inj urious action ofthe chemical solution, with a lining of lead, and also with a lining composed, essentially, of acid-resisting tiles secured by seams of lead as a tamping, the said seams or tamping being secured to the Tiles have also been used as alining secured by means of a tamping of cement and interlocked with each other.

My invention relates more particularly to a lining for pulp-digesters composed of acid-resisting tiles or blocks, and has for its object to provide means, as will be described, by which the tiles or blocks are more effectually secured in place within the boiler, the said tiles being capable of being readily removed for repair or other purposes. l

My invention therefore consists, essentially, in the combination, with a boiler-shell and an acid-resisting lining therefor, composed of tiles or blocks, of independent metallic boxes or cradles secured to the said shell, and in which the said tiles orblocks are secured, substantially as Will be described. The boiler-shell on its inner side may and preferably will have applied to it a coating or iilm of acid-resisting material, preferably ozoceriteV or its refined product, ceresin, and when the boxes or cradles are made of phosphor-bronze or otheracid-resisting metal a layer of sheet-lead will preferably beinterposed between the said phosphor-bronze or acid-resisting metal boxes or cradles and the boiler-shell, the coating or iilm of ozocerite being applied to the said shell so as to form a cushion for the sheet-lead. The boxes or cradles when made of iron or steel will preferably be covered on their inner and outer sides with ozocerite.

Other features of my invention will be pointed out in the claims at the end of this specification. Y

Figure l is a vertical longitudinal section of a pulp boiler or digester provided with an acid-resisting lining embodyingmy invention, the said boiler being broken out to save space in the drawings, the upper part of the boiler being provided with an acid-resisting lining` differing from that of the lower part of the boiler, as will be described. Fig. lf is a detail to be referred to. Fig. 2 represents the inner side of a sufficient portion of the boiler to enable my invention to be understood, the lining being partially broken out. Fig. 3 is a section of the portion of the boiler shown in Fig. 2 on line x fr; Fig. 4, a section of the boiler on line y y, Fig. 2; Fig. 5, a detail in perspective of one of the boxes to more clearly show the manner of constructing the same outside the boiler; Fig. 6, a section of a modified form of lining to be referred to, and Fig. 7 a detail of the phosphor-bronze or acid-resisting. metal box or cradle.

A represents the outer steel or iron shell of a boiler or digester, having a cylindrical body 2 and a conical top 3 and bottom 4, provided With extensions forming man-holes.

In accordance with my invention the boiler-shell has secured to it on its inner side, as by threaded bolts a, a lining made of independent detachable sections, each comprising| an acid-resisting tile a4 and a metallic box or cradle a', the said metallic boxes or cradles being preferably of iron or steel; but they Inay be of phosphor-bronze or other like acidresisting composition. When made of iron or steel, the boxes or cradles will preferably be covered on their innerand outer sides with ozocerite.

The detachable metallic boxes or cradles a are made substantially shallow, as shown in Figs. 3 and 5, and are composed of a bottom a2 and sides a3, and each box or cradle has placed within it the acid-resisting tile a4, preferably of glass, porcelain, or other silicious material, the said box or cradle when made of iron or steel being preferably made without ends, as shown in Fig. 5, and having placed in it a layer a5 of lead or other acid IOO resisting material, which is made to conform to the shape of the said box or cradle, the said layer being interposed between the said box and the tile therein. The layer a of lead is provided with end flaps a, (see Fig. 5,) which in practice are bent or turned up against the ends of the tile, so that when the box or cradle and its tile a4 are ready to be placedy in position in the boiler the said tile a4 will have its sides incased in lead.

The shallow boxes or cradles are placed within the boiler so that they abut at the upi per or inward edges of their sides, the opening between the sides being shown as exaggerated in Fig. 3, and the end flaps a of leadabut against each other, as shown in Fig. 4.

The lead layers are not shown in Fig. l in or The der to avoid confusion in the drawings. sides of the lead layers c5 are bent over so as to lie upon the edge of the sides a3 of the boxes, and are preferably beveled, as at b, (see Fig. 3,) so that a channel is formed by the beveled sides of adjacent layers, into which lead fused by the action of a blow-pipe is run, the flame of the said blow-pipe also fusing the edges of the aforesaid adjacent lead layers, as indicated at b', thus firmly uniting the sides of adjacent layers a5 with the fused lead and forming a liquid-tight joint.

The tiles a4 are provided, as shown, with side flanges 123,(see Fig. 3,) which overlap and rest upon the lead layer a5, the said flanges of adjacent tiles coming near together and leaving between them but a substantially small space, as clearly shown in Figs. 3 and 5, so that only a small area of lead surface in the boiler is exposed to the heal of the boiler, thereby obviating creeping of the lead. The

` end flaps a of each layer a5 are also preferably beveled, as at b4, (see Fig. 4,) and the abutting end flaps of adjacent sections form achannel into which lead is fused by the flame of a blow-pipe, as indicated at b5, Fig. 4, the said flame of the blow-pipe fusing the aforesaid adjacent sections together, and with the additional lead making the whole integral, and thereby forming a Iliquid-tight joint.

Instead of making the tile a4 of glass, porcelain, brick, duc., it maybe made of an acidresisting composition-such, for instance, as a composition of seven parts lead and one part antimonyf-the said tile being made as a hollow shell, (see Fig. 3,) into which a filling c of plaster-of-paris and a hardening materialsuch as sand or other suitable material-is packed forthe purpose of sustainingthe pressure within the boiler while in operation.

When the boxes or cradles are composed of phosphor-bronze or like acid-resistin g composition, the lead layers a5 may be omitted and the tile rest directly on the said boxes7 as shown in Fig. G, and also in Fig. l, the said boxes being provided with upturned sides f3 and ends f4, (see Fig. 7,) so that the upper or inward edges of the sides and the ends ot' adjacent boxes substantially abut, and are rendered liquid-tight by burning or fusing a suitable hard solder upon the exposededges of the said boxes, whereby all the boxes or cradles in the boiler or digester are made integral and an acid-proof protection to the outer shell of the digester obtained. As shown in Fig. l, the lower half of the boiler or digester is lined in this manner. As an additional protection l may cover the inner surface of the shell of the boiler' with sheetlead prior to bolting in place the phosphorbronze or acid-resisting metal boxes or cradles, as indicated at f in the left of Fig. 3 and in the lower half of Fig. l.

lf in practice the tiles in the central portions of the body, top, and bottom of the boiler become broken,they may be readily removed individually by melting the hard solder or lead joint b', (as by means of a blowpipe,) so as to loosen the said joint and permoved without disturbing the rest of the lining. When the tiles at the angle formed by the junction of the cylindrical body 2 and the conical top and bottom 3 4 are to be removed, the adjacent tile above or below the broken one must first be removed, and then the cradle containing the broken tile may be moved into the space thus left vacant and removed therefrom. The last two tiers of tiles in the top and bottom must also be removed in like manner. 'The box or cradle may be removed from the boiler and the broken tile replaced in the box by a new tile, and the said box and its tile again placed in position within the boiler.

Referring to Figs. l and 2, it will be seen that the iron-shell A in practice is protected by a continuous sheet of lead and the lead by the tiles.

Referring to Fig. l,the boiler-shell A at its upper man-hole has secured to it, as by rivets d,- an annular ring d', provided with a flange (l2. The upper end or edge of the ring d is preferably flush with the end or edge of the boiler-shell A and the boxes or cradles a', and tiles a4, and the said ring, boiler-shell, tiles, and boxes, are covered with an annular strip or ring cl3 of lead, upon which rests an annular cap d of phosphor-bronze or other acid-resistin g composition, provided with side flanges d5, which overlap the lead sheet d3.

The annular cap d4 is provided with an annular socket` or groove in itsv upper face, formed as shown by flanges d, and the said cap is secured to the shell of the boiler and the upper boxes or cradles by bolts (Z7, having their lower ends engaging with said boxes or cradles, and having their upper ends embedded in the said groove or socket, and covered with an annular strip or washer d8 of lead.

The upper man-hole, in practice, is closed by a cover composed of a metallic shell B', having a central opening,into which is fitted a casting or sleeve d10, having a central boss or hub CP2, joined to the sleeve by arms el, (see Fig. 1%) the said casting being extended i mit the cradle or box and its tile to be re- 1 IOO IIO

below the under face of the cover B', and provided with a fiange C125, between which and the said cover is clamped by means of screwbolts @Z13 one edge of an annular sheet e of lead or otherI acid resisting material, the outer end or edge of the said sheet being clamped to the said cover by an annulairing e of phosphor-bronze secured by bolts e2, the said annular ring having an annular projection e3, which fits into the groove in the cap d4 and is forced against the lead washer d8 to effect a liquid-tight joint by the bolts e5, extended through the flange d2 and the cover B.

The edge e of the casting or sleeve d10 forms a seat for a valve e7, having its stem es extended through the boss or hub CP2, the said valve-stem beyond the cover being provided with a screw-thread to be engaged by the threaded hub of a wheel e9, the said wheel in practice being rotated in one direction to force the valve eT to its seat e6. When the boiler is in use, the pressure within will keep the said valve firmly seated, so that when the bleached and cooked pulp is ready to be discharged the wheel may be rotated in the opposite direction and run up on the threaded valve-stem, so as to permit the valve to be instantly opened by the atmospheric pressure,the weight of the wheel assisting at the moment the pressure within the boiler is reduced and before a vacuum can be formed, whereby collapsing of the lining is obviated.

Instead of the hand-wheel e9, I may use a nut. It will be noticed that the hand-wheel acts as a weight to assist the atmospheric pressure to open the valve substantially in an instant and before a vacuum is formed.

I have herein shown the valve as located in the cover B; but it is evident it may be located in other parts of the boiler.

The lower man-hole is provided with a cap or cover B2, similar to the cap or cover B', and the said lnan-hole is rendered liquidand gas tight in a similar manner to the upper man-hole, like partsbeing designated by like letters.

The cap or cover B2 is provided with a preferably central opening, through which is extended a thimble or sleeve p, secured to the cover B2, as by bolts p20, and provided, as shown, with screw-threads to be engaged by a threaded nut px, over which is slipped a casting or fitting p', secured to the said cover, as by bolts or screws p2.

The casting or fitting' p is provided, as shown, with two ports p3 p4, with which may communicate outlet-pipes. (Not shown.)

The casting or fitting p forms the valvechest for a valve p6, (shown as a disk-valve,)V

having its valve-stein p7 extended through a cover p8 for the said valve-chest, the said valve-stein being provided, as shown, with screw-threads to engage a threaded opening in a bar p10, secured to the cover p8, as by bolts p12, the said Valve-stein beyond the bar p1 being provided with a suitable handwheel p13.

The outer end of the thimble or sleeve p forms the seat for the valve p6.

It will be noticed that the acid-resisting lining of tiles is extended through the manholes and forms an acid-resisting covering for the inner walls or sides -of the said manholes.

The finished product of the dig-ester is blown out and the digester emptied through the thimble p.

The boilershell will preferably have applied to it on its inner side a coating or film of acid-resisting material, preferably ozocerite or its refined product, ceresin, as indicated by heavy dark line 20, Fig. la.

l. In a boiler or digester for the manufacture of pulp, the combination, with the boilershell and an acid-resisting lining therefor composed of tiles or blocks, of independent metallic boxes or cradles secured to the said shell, and in which the said tiles or blocks are placed, substantially as described.

2. In a boiler or digester for the manufacture of pulp, the combination, with the boilershell and an acidresisting lining therefor composed of tiles or blocks, of independent metallic boxes or cradles secured to the said shell, and composed of a bottom a2 and sides a3, and a layer a5 of lead or acid-resisting material interposed between said boxes or cradles, and tiles or blocks, substantially as described.

3. In a boiler or digester for the manufacture of pulp, the combination, with the boilershell and an acid-resisting lining therefor consisting of tiles made as of hollow shells, pro. vided with a filling c in said hollow shells, of metallic boxes or cradles secured to the said IOO boiler-shell and consisting of a bottom a2 and y sides a3, and a layer of acid-resisting material between said boxes and tiles, substantially as described.

1l. In a boiler or digester for the manufacture of pulp, the combinatiomwith the boiler'- shell and an acid-resist-ing lining therefor composed of tiles, of independent metallic boxes or cradles secured to the said boilershell, and composed of a bottom a2 and sides a3, and a layer a5 of lead interposed in said box or cradle between the said tile and cradle, and having end flaps a6 to be turned up against the end of the tile, substantially as described.

5. The combination, with the shell of a digester, of tiles, metallic cradles for holding said tiles, and means for rigidly securing the cradles to the shell, substantially as described.

6. The combination, with the boiler having a man-hole and provided with an acid-resist# inglining composed of tiles and metallic boxes or cradles, of an annular cap for said inanhole secured to said boxes, and a cover provided with an annular ringto engage said cap to form a liquid-tight joint, and means, substantially as described, to secure said cover to the boiler, as and for the purpose set forth.

IIO

7. The combination, with a boiler having a man-hole and provided with an acid-resistin g vlining composed of tiles and metallic boxes or cradles, of an annular' cover for said man-hole .secured to said boxes and provided with a groove, a lead ring or washer in said groove, a metallic cover B', provided with a lining e of lead, and an annular ring e', secured to said man-hole, and means to secure said cover I to the boiler, substantially as described.

9. The outer shell of a di gestor for the manufacture of pulp, comprising a cylindrical body7 provided with a conical bottom and top or ends, and with cylindrical extensions forming man-holes in the said bottom and top or ends, in combination with an acid-resisting lining` for the inner walls of the said shell and manholes of said dgester, made of a series of independent detachable sections comprising an acid-resisting tile, a metallic box or cradle secured to the said shell of the digester, as by bolts a, and having a bottom d'2 and sides a3, in which the said tile is placed, and a layer a5 of lead or other acid-resisting material interposed between the said box or cradle and the acid-resisting tile, covers for said bottom 1 and top man-holes, and means to secure said covers to the said di gester-shell, substan ially as described.

10. The outer shell of a digester for the manufacture of pulp, comprising a cylindrical body provided with a conical bottom and top or ends,and with cylindrical extensions forming man-holes in the said bottom and top or ends, in combination with an vacid-resisting lining for the inner walls of the said shell and man-holes of said digester, made of a series of independent detachable sections, each comprising an acid-resisting tile and an acid-resisting metallic box or cradle secured to the shell of the digester, as by bolts a, and having a bottom ax, sides a3, and ends a2, in which the said tile is secured, and a layer f of lead or other acid-resisting material interposed between the said acid-resisting metallic boxes or cradles and the said shell of the digester, covers for the said man-holes, and means to secure said covers to the shell of the said digester, substantially as described.

l1. In a boiler or digester for the manufacture of pulp, t-he combination, with the boilershell, of an acid-resisting lining therefor made v, of independent detachable sections, each comprising an acid-resisting tile and a box or cradlehaving a bottom a2 and sides a3, in

which the said tile is placed, and a coating of ozocerite applied to the boiler-shell, substantially as described.

l2. In a boiler or digester for the manufacture of pulp, the combination, with the boilershell, of an acid-resistin g lining therefor made of independent detachable sections, each comprising an acid-resisting tile and a box or,

cradle having a bottom a2 and sides. a3, in which the said tile is placed, and a coating of ozocerite applied to the said boxes or cradles, substantially as described.

13. In a boiler or digester for the manufacture of pulp, the combination, with the boilershell, of an acid-resisting lining therefor made of independent detachable sections, each comfposed of an acid-resisting tile or block and a box or cradle to hold the same, and a layer ofacid-resisting material between said box and boiler-shell, substantially as described.

14. In a boiler or digester for the manufacture of pulp, the combination, with the boilershell, of an acid-resisting lining therefor made of independent detachable sections, each composed of an acid-resisting tile or block and a box or cradle to hold the same, and a layer of acid-resisting material between said box and boiler-shell, and a coating of ozocerite applied to the interior of said boiler-shell, substan-y tially as described.

In testimony whereof I have signed my name to this speciiication in the presence of two subscribing witnesses.

RICHARD LAVERY.

Vitnesses: c JAs. H. CHURCHILL, MABEL RAY. 

